Memory, toner cartridge, developing device and image forming apparatus having the same

ABSTRACT

A toner cartridge, a developing device, and an image forming apparatus, in which a memory is provided in the cartridge to be accessible by an image forming apparatus are disclosed. The image forming apparatus includes a developing device detachably attached to the body the image forming apparatus, and a toner cartridge detachably disposed in the developing cartridge, which includes a memory accessible from a surface of the toner cartridge exposed outside the developing cartridge when the toner cartridge is installed in the developing cartridge.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 from Korean PatentApplication No. 10-2008-0016472, filed on Feb. 22, 2008, in the KoreanIntellectual Property Office, the disclosure of which is incorporatedherein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Aspects of the present invention relate to an image forming apparatus,and more particularly, to a replaceable toner cartridge having a memory,a developing cartridge, a developing device, and an image formingapparatus having the same.

2. Description of the Related Art

General image forming apparatuses such as, e.g., printers, copymachines, fax machines, or multifunctional peripherals print images onprinting media using a quantity of toner.

The more pages are printed, the more toner is consumed, and thus thetoner needs to be periodically replenished. The toner may beaccommodated in a developing cartridge removably installed in the bodyof the image forming apparatus, together with other components, e.g., adeveloping roller and/or a supply roller.

To replenishing toner, when the entire developing cartridge is replaced,not only the toner, but also other components, such as, e.g., thedeveloping roller and/or supply roller are also replaced, causing thecost of operational and/or maintenance cost of the image formingapparatus to increase.

The developing cartridge may include a memory such as, e.g., a customerreplaceable unit monitor (CRUM), that stores information that can beused to determine, for example, whether the developing cartridge ismounted, the amount of toner remaining, and/or other printing relatedinformation.

As various internal components and the driving mechanism to drive theseinternal components are also disposed in or about the developingcartridge, the placement of the memory device, e.g., a CRUM, at alocation that does not contribute greatly to the overall size of thedeveloping cartridge and/or the image forming apparatus, and that alsoallows the memory device to transmit and/or receive signals to and/orfrom the image forming apparatus, is desirable.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present invention will be more apparent from thedescriptions of embodiments herein with reference to the accompanyingdrawings, in which:

FIG. 1 is a perspective illustrating the mounting of a developing devicean image forming apparatus according to an embodiment of the presentinvention;

FIG. 2 is a sectional view illustrating the developing device of FIG. 1;

FIGS. 3A and 3B are perspective views illustrating the mounting of atoner cartridge in a developing cartridge according to an embodiment ofthe present invention; and

FIG. 4 is a sectional view showing the relevant internal features of atoner cartridge mounted in a developing cartridge according to anembodiment of the present invention.

DETAILED DESCRIPTION OF SEVERAL EMBODIMENTS

Certain exemplary embodiments of the present invention will now bedescribed in greater detail with reference to the accompanying drawings.

In the following description, the same drawing reference numerals areused for the same elements even in different drawings. While theforegoing embodiments are described with detailed construction andelements to assist in a comprehensive understanding of the embodiments,it should be apparent however that the embodiments can be carried outwithout those specifically detailed particulars. Also, well-knownfunctions or constructions will not be described in detail so as toavoid obscuring the description with unnecessary detail.

FIG. 1 is a perspective view showing a developing device being mountedin an image forming apparatus according to an embodiment of the presentinvention. Referring to FIG. 1, an image forming apparatus 1 may includea body 10 and a developing device 100.

The body 10 (only an outline of which is shown) may includes parts toperforming operations to print an image on a printing medium transferredalong a printing path including, for example, a feeding unit, fusingunit, and/or transferring unit, or the like. Functions of these partshoused in the body 10 for printing an image are well known to thoseskilled in the art, so a detailed description is omitted here for thesake of brevity.

FIG. 2 is a sectional view illustrating the developing device 100 shownFIG. 1. The developing device 100 may include a developing cartridge 110and a toner cartridge 120.

The developing cartridge 110 may be detachably supported in the body 10of the image forming apparatus 1. More specifically, the inside of thebody 10 may be accessed by opening a cover 11 as shown in FIG. 1,allowing the developing cartridge 110 to enter the body 10 in thedirection indicated by arrow A1, and to be mounted within a casing 12 ofthe body 10.

A handle 112 to be grasped by a user may be formed on the developingcartridge 110 so as to make the extraction of the developing cartridge110 easier. The handle 112 may be folded toward the developing cartridge110 when the developing cartridge 110 is mounted in the body 10, and maybe unfolded from the developing cartridge 110 when the developingcartridge 110 is to be detached from the body 10, so the user canconveniently grasp the handle 112. As shown in FIGS. 3A and 3B,according to an embodiment, one end of the handle 112 may be pivotallyfixed to the developing cartridge 110, so the opposite end of the handle112 may rotate.

The developing cartridge 110 may include a developing cartridge body 111having the external appearance shown in FIGS. 2 and 3. The developingcartridge body 111 may support therein a photoconductive medium 20, adeveloping roller 113 and a supply roller 114. The developing roller 113develops a latent image of the photoconductive medium 20 using toner,and the supply roller 114 supplies the toner to the developing roller113.

In this embodiment, the photoconductive medium 20 is housed in thedeveloping cartridge 110, but this is merely an example. As it should beapparent to those skilled in the art, the photoconductive medium 20 mayalternatively be provided separately on the image forming apparatus body10 rather than in the developing cartridge body 111.

The developing cartridge 110 according to an embodiment may be insertedinto the casing 12 in the direction indicated by the arrow A1 (see FIG.1), which may be substantially perpendicular to the rotating shafts 113a and 114 a of the developing roller 113 and the supply roller 114, andmay be mounted in the casing 12. Accordingly, both side edges of thedeveloping cartridge 110 may be supported in place between the casing 12and the image forming apparatus body 10.

According to an embodiment, the developing cartridge body 111 may itselfaccommodate a quantity of toner, so as to allow a number of pages to beprinted even without a supply of toner from the toner cartridge 120.

The toner cartridge 120 may be detachably supported in the developingcartridge 110. To this end, a recess 117 to house the toner cartridge120 may be formed in the developing cartridge body 111.

The recess 117 is formed in the developing cartridge 110 with apredetermined depth so that the toner cartridge 120 may be inserted inthe direction indicated by arrow B1 (see FIG. 3A), which may besubstantially parallel to shafts 113 a and 114 a of the developingroller 113 and the supply roller 114.

The direction indicated by the arrow A1, in which the developingcartridge 110 is mounted in the body 10 of the image forming apparatus1, may be referred to hereinafter as the first direction, and thedirection indicated by the arrow B1, in which the toner cartridge 120 ismounted in the developing cartridge 110, may be referred to as thesecond direction.

Guide grooves 117 a and 117 b may be formed in the recess 117 in orderto guide the toner cartridge 120 to be mounted as shown in FIG. 3A.Mounting guides 124 and 125 corresponding to the guide grooves 117 a and117 b may be formed on the toner cartridge 120 as shown in FIG. 2. Inthis embodiment, two guide grooves 117 a and 117 b are formed on bothsurfaces of the recess 117, and two mounting guides 124 and 125corresponding to two guide grooves 117 a and 117 b are formed in thetoner cartridge 120, but the number of guide grooves and mounting guidesis not so limited, and only one of each or more than two of each mayalternatively be provided.

A blocking member (not shown) corresponding to the recess 117 may bemounted in the recess 117 in order to prevent the toner accommodated inthe developing cartridge body 111 from leaking out when the tonercartridge 120 is not housed in the developing cartridge 110.

A toner transferring member 122 may be rotatably mounted within thetoner housing 121 containing the toner as shown in FIG. 4, and maysupply the toner to the developing cartridge body 111. The tonertransferring member 122 transfers the toner toward a toner supplyopening 123 (referring to FIG. 2) formed on the bottom surface of thetoner cartridge 120.

The toner contained in the toner housing 121 of the toner cartridge 120is transferred to the toner supply opening 123 by the toner transferringmember 122, then to the developing cartridge body 111 through the tonersupply opening 123, and in turn sequentially to the supply roller 114,and to the developing roller 113, which uses the toner to develop alatent image formed on the photoconductive medium 20. According to anembodiment, first and second agitating members 115 and 116 may berotatably mounted in the developing cartridge body 111 in order toagitate the toner prior to supplying the toner to the supply roller 114.While two agitating members are shown and described, the number of theagitating member(s) is not so limited, and any number of agitatingmembers may alternatively be provided.

The developing roller 113, the supply roller 114, and the first andsecond agitating members 115 and 116 are provided in the developingcartridge 110 to sequentially transfer the toner in the developingcartridge 110.

When the toner cartridge 120 is mounted in the developing cartridge body111, the transferring member 122 may be driven by a driving mechanismprovided in the developing cartridge 110. The driving force may betransferred to the toner transferring member 122 at the leading end 120a, which is inserted first into the recess 117 based on the directionB1, in which the toner cartridge 120 is inserted into the recess 117.

A driven shaft 122 a of the toner transferring member 122 protrudes fromthe front end 120 a of the toner cartridge 120 as shown in FIG. 4. Thedriven shaft 122 a is coupled to a driving shaft 110 a of the developingcartridge body 111 (e.g., through engagement of one or more gears),thereby the toner transferring member 122 thereby receives the drivingforce.

According to an embodiment, the toner transferring member 122 mayreceive the driving force, e.g., from the developing roller 113 and/orthe supply roller 114 formed in the developing cartridge body 111through a gear train (not shown).

A memory 130 is mounted in the toner cartridge 120 for use indetermining the condition of the toner cartridge 120. The memory 130 iscapable of transmitting and/or receiving signals to and/or from theimage forming apparatus 1 to allow the determination of, e.g., whetherthe toner cartridge 120 is mounted in the developing cartridge 110, thetoner consumption, printing related information, or the like.

The memory 130 may be disposed at such location to be accessible from asurface of the toner cartridge 120 that is exposed externally from thedeveloping cartridge body 111 when the toner cartridge 120 is mounted inthe recess 117, so that a signal communication may be establishedbetween the memory 130 and the image forming apparatus 1.

For example, according to an embodiment, the memory 130 (or the accessterminals thereof) may be disposed on the surface of the trailing end120 b of the toner cartridge 120 that trails the leading end 120 aduring mounting with respect to the direction indicated by the arrow B1,the trailing end 120 b being exposed to the exterior of the developingcartridge body 111 when the toner cartridge 120 is properly mounted inthe recess 117.

The memory 130 may include a plurality of terminals 131, 132, 133 and134, which may be arranged, each with a predetermined length along thedirection parallel to the direction of the arrow A1, and may makecontact with contact 13 (e.g., a number of contacts each correspondingto one of the terminals 131, 132, 133, 134—for brevity sake collectivelyreferred to as the contact 13) formed in the body 10 of the imageforming apparatus 1. The contact 13 may be formed along a directionparallel to the direction in which the developing cartridge 110 ismounted, and may be, e.g., a plate spring of a predetermined length thatprotrudes into the casing 12.

According to an embodiment, at least one of the plurality of terminals131, 132, 133 and 134 may be made to be longer than the others. Thelongest terminal may be, e.g., a ground terminal.

The plurality of terminals 131, 132, 133 and 134 in FIGS. 3A and 3B arereferred to below as first to fourth terminals. The first terminal 131may be used as a common collector voltage (Vcc) terminal to supplypower, the second terminal 132 may be used as a data and/or controltransmission terminal, the third terminal 133 may be used as a clockterminal to receive clock signals, and the fourth terminal 134 may beused as a ground terminal. The fourth terminal 134 may be longer thanthe other terminals 131, 132 and 133, and may be placed below the otherterminals 131, 132 and 133. The fourth terminal 134 extends further thanthe other terminals 131, 132 and 133 in the direction indicated by arrowA1, so as to first contact the contact 13 attached to the body 10 of theimage forming apparatus 1 when the developing cartridge 110 is mounted.

According to an embodiment, an oblique surface 135 may be provided asbeing sloped in the direction indicated by the arrow A1 to absorb theimpact between the memory 130 and the contact 13 when the developingcartridge 110 is mounted in the body 10 of the image forming apparatus 1as shown in FIG. 3B. The oblique surface 135 may act to reduce theimpact between the terminals 131, 132, 133, 134 and the contact 13 whenthe developing cartridge 110 is mounted.

When the developing cartridge 110 is mounted in the body 10 in thedirection indicated by the arrow A1, the oblique surface 135 presses thecontact 13, which may be, e.g., a plate spring protruding towards thecasing 12, so that the contact 13 gradually retracts due to the slope ofthe oblique surface 135 before contacting the terminals 131, 132, 133and 134.

That is, the oblique surface 135 may be used to gradually press in thecontact 13 as the developing cartridge 110 is being mounted in the body10 of the image forming apparatus 1. To that end, the oblique surface135 may be disposed at the upstream of the memory 130 with respect tothe direction of the arrow A1, so that the oblique surface 135 may pressthe contact 13 prior to the terminals 131, 132, 133 and 134 coming intocontact with the contact 13.

When the developing cartridge 110 housing the toner cartridge 120 isinserted in the body 10, with the above described arrangements, thememory 130 disposed on the toner cartridge 120 makes an electricalconnection with the contact 13, and is able to transmit signals toand/or receive signals from the image forming apparatus 1.

The process of replacing the developing device of the image formingapparatus 1 according to an embodiment of the present invention will beexplained with reference to FIGS. 1 to 4.

When the toner cartridge 120 needs to be replaced, e.g., when the toneris exhausted, the user detaches the developing cartridge 110 from thecasing 12 in the direction indicated by the arrow A2 as shown in FIG. 1.

The user then detaches the empty toner cartridge 120 in the directionindicated by the arrow B2 as shown in FIG. 3A, and inserts a new tonercartridge 120 filled with a supply of toner into the developingcartridge body 111 along the recess 117 in the direction indicated bythe arrow B1.

When the toner cartridge 120 is completely mounted in the recess 117,the memory 130 disposed on a trailing end 120 b of the toner cartridge120 is exposed to the exterior of the toner cartridge body 111 throughthe recess 117 as shown in FIG. 3B. Referring to FIG. 4, the drivenshaft 122 a is engaged with the driving shaft 110 a, thereby driving thetoner transferring member 122.

The developing cartridge 110 with the new toner cartridge 120 mountedenters the body 10 in the direction indicated by the arrow A1 in FIG. 1,and is mounted in the casing 12 of the body 10. The plurality ofterminals 131, 132, 133 and 134 are parallel to the arrow A1, and areformed having a predetermined length, so the memory 130 establishes acontact with the body 10.

The plurality of terminals 131, 132, 133 and 134 contact the contact 13,so the information regarding, e.g., whether the toner cartridge 120 ismounted, the amount of remaining toner, or printing information may betransferred to the body 10 of the image forming apparatus 1.

According to an embodiment of the present invention, a replaceable tonercartridge that can be detachably installed in the developing cartridge,the replaceable toner cartridge including a memory, which is accessiblethrough terminal or terminals disposed on the surface of the exposed endof the toner cartridge that remains exposed when the toner cartridge isinstalled in the developing cartridge.

According to an embodiment, the developing cartridge may be detachablymounted in an image forming apparatus. When the developing cartridge ismounted in place in the image forming apparatus, the terminal orterminals for accessing the memory come(s) in contact with contactterminal provided in the image forming apparatus so as to establishsignal communication between the memory and the image forming apparatus.

Furthermore, the toner cartridge may house therein a toner transfermember that is driven from the opposite end to the exposed end.

The foregoing exemplary embodiments and advantages are merely exemplaryand are not to be construed as limiting the present invention. Thepresent teaching can be readily applied to other types of apparatuses.Also, the description of the exemplary embodiments of the presentinvention is intended to be illustrative, and not to limit the scope ofthe claims, and many alternatives, modifications, and variations will beapparent to those skilled in the art.

1. A developing apparatus, comprising: a developing cartridge havingformed therein a recess having a depth extending into the developingcartridge; a toner cartridge detachably mounted in the recess of thedeveloping cartridge, the toner cartridge having an exposed surface thatis at least partially exposed outside the developing cartridge when thetoner cartridge is mounted in the recess; and a memory accessible viathe exposed surface.
 2. The developing apparatus of claim 1, furthercomprising: a rotational member supported in the developing cartridgesuch that the rotational member is rotatable about a rotating shaft,wherein the toner cartridge is received into the recess in a firstdirection substantially parallel to the rotating shaft.
 3. Thedeveloping apparatus of claim 2, wherein the recess comprises at leastone guide groove parallel to the first direction, and the tonercartridge comprises at least one guide protrusion receivable into the atleast one guide groove.
 4. The developing apparatus of claim 2, whereinthe memory being accessible through one or more access terminalsarranged on the exposed surface, the developing cartridge beingdetachably supported in a body of an image forming apparatus, thedeveloping cartridge being received into the body in a second directionsubstantially perpendicular to the rotating shaft, the one or moreaccess terminals each having a respective length extending parallel tothe second direction.
 5. The developing apparatus of claim 4, whereinthe one or more access terminals comprises a plurality of terminals, atleast one of the plurality of terminals having its respective lengthlonger than other ones of the plurality of terminals.
 6. The developingapparatus of claim 5, wherein the at least one of the plurality ofterminals is located closest to a bottom surface of the toner cartridgeas compared with other ones of the plurality of terminals.
 7. Thedeveloping apparatus of claim 5, wherein the at least one of theplurality of terminals is a ground terminal.
 8. The developing apparatusof claim 4, wherein the exposed surface comprises a first surface, onwhich the one or more access terminals are supported, and an obliquesurface formed upstream of the first surface with respect to the seconddirection.
 9. The developing apparatus of claim 8, wherein the obliquesurface slopes downward as moving away from the first surface in thesecond direction.
 10. The developing apparatus of claim 2, wherein therotational member comprises: a photoconductive medium supported on afirst rotational shaft; a developing roller supported on a secondrotational shaft, the developing roller being configured to rotate tothereby supply toner to the photoconductive member; and one or moretoner transferring members supported on its own respective rotationalshafts, the one or more toner transferring members being rotatable tocause a movement of toner toward the developing roller, wherein thefirst rotational shaft, the second rotational shaft and the respectiverotational shafts of the one or more toner transferring members extendare substantially parallel to each other.
 11. The developing apparatusof claim 1, wherein the toner cartridge includes a leading end, whichfirst enters the recess when the toner cartridge is received into therecess, and a trailing end opposite the leading end, the exposed surfacebeing an external surface of the trailing end, and wherein the tonercartridge comprises a toner transferring member supported on a drivenshaft that receives a driving force from an external source at theleading end to thereby rotate the toner transferring member about thedriven shaft to cause developer housed in the toner cartridge to movetoward the developing cartridge.
 12. The developing apparatus of claim1, wherein the developing cartridge further comprises a foldable handle.13. The developing apparatus of claim 1, wherein the memory comprises acustomer replaceable unit monitor (CRUM).
 14. An image formingapparatus, comprising: a main body; a developing cartridge detachablysupported in the main body; a toner cartridge detachably supported inthe developing cartridge, the toner cartridge being configured to supplytoner to the developing cartridge; and a memory accessible via anexposed surface of the toner cartridge, the exposed surface being atleast partially exposed outside the developing cartridge when the tonercartridge is supported in the developing cartridge.
 15. The imageforming apparatus of claim 14, wherein the developing cartridgecomprises a housing recess into which the toner cartridge is received,the exposed surface being exposed when the toner cartridge is receivedin the housing recess.
 16. The image forming apparatus of claim 15,wherein the housing recess comprises at least one housing guide grooveparallel to the first direction, and the toner cartridge comprises atleast one guide protrusion receivable into the housing guide groove. 17.The image forming apparatus of claim 15, wherein the toner cartridgecomprises: a toner housing to accommodate toner therein; a leading end,which first enters the housing recess when the toner cartridge isreceived into the housing recess; a trailing end opposite the leadingend, the exposed surface being an external surface of the trailing end,and a toner transferring member supported on a driven shaft thatreceives a driving force from an external source at the leading end tothereby rotate the toner transferring member about the driven shaft tocause developer accommodated in the toner housing to move toward thedeveloping cartridge.
 18. The image forming apparatus of claim 17,wherein the driven shaft of the toner transferring member protrudesoutward away from the leading end of the toner cartridge.
 19. The imageforming apparatus of claim 14, wherein the developing cartridgecomprises: a rotational member supported in the developing cartridgesuch that the rotational member is rotatable about a rotating shaft,wherein the toner cartridge is received into the recess in a firstdirection substantially parallel to the rotating shaft, the developingcartridge being received in the main body of the image forming apparatusin a second direction substantially perpendicular to the rotating shaft.20. The image forming apparatus of claim 19, wherein the rotationalmember comprises: at least one of a photoconductive member, a developingroller and a supply roller, each supported on a respective rotatingshaft.
 21. The image forming apparatus of claim 19, further comprising:one or more access terminals arranged on the exposed surface, the memorybeing accessible through the one or more access terminals, each of theone or more access terminals having a respective length extendingparallel to the second direction; and one or more contacts arranged onthe main body of the image forming apparatus such that each of the oneor more contacts come into contact with corresponding respective one ofthe one or more access terminals to thereby establish signalcommunication between the memory and the image forming apparatus. 22.The image forming apparatus of claim 21, wherein the one or morecontacts comprises at least one plate spring that retractably protrudesinwardly into the main body to be in pressing contact with the one ormore access terminals.
 23. The image forming apparatus of claim 21,wherein the one or more access terminals comprises a plurality ofterminals, at least one of the plurality of terminals having itsrespective length longer than other ones of the plurality of terminals.24. The image forming apparatus of claim 23, wherein the at least one ofthe plurality of terminals is located closest to a bottom surface of thetoner cartridge as compared with other ones of the plurality ofterminals.
 25. The image forming apparatus of claim 23, wherein the atleast one of the plurality of terminals is a ground terminal.
 26. Theimage forming apparatus of claim 21, wherein the exposed surfacecomprises a first surface, on which the one or more access terminals aresupported, and an oblique surface formed upstream of the first surfacewith respect to the second direction so that the oblique surface comesinto contact with the one or more contacts first before the one or moreaccess terminals as the developing cartridge moves into the main body.27. The image forming apparatus of claim 26, wherein the oblique surfaceslopes downward as moving away from the first surface in the seconddirection.
 28. The image forming apparatus of claim 14, wherein thememory comprises a customer replaceable unit monitor (CRUM).
 29. A tonercartridge, comprising: a toner cartridge body defining an inner volumein which to accommodate toner; a toner transferring member rotatablymounted in the toner cartridge body, the toner transferring member beingconfigured to receive, at a first end of the toner cartridge body, adriving force from an external driving force source, and configured torotate to thereby move the toner in the toner cartridge body to anoutside the toner cartridge; and a memory accessible through one or moreaccess terminals arranged on a surface of a second end opposite thefirst end of the toner cartridge body when the toner cartridge ismounted.
 30. The toner cartridge of claim 29, wherein the tonertransferring member is supported on a rotating shaft that extends alonga first direction, and wherein the one or more access terminalscomprises a plurality of terminals each having a respective lengthextending in a second direction perpendicular to the first direction, atleast one of the plurality of terminals having its respective lengthlonger than other ones of the plurality of terminals.
 31. The tonercartridge of claim 30, wherein the at least one of the plurality ofterminals is located closest to a bottom surface of the toner cartridgebody as compared with other ones of the plurality of terminals.
 32. Thetoner cartridge of claim 31, wherein the surface of the second endcomprises a first surface, on which the one or more access terminals aresupported, and an oblique surface that slopes downward as moving awayfrom the first surface along the second direction.
 33. The tonercartridge of claim 29, wherein the memory comprises a customerreplaceable unit monitor (CRUM).
 34. An apparatus, comprising: a memoryaccessing unit having a main body, the main body including one or morecontact terminals; a first detachable unit detachably supported in themain body, the first detachable unit being receivable into the main bodyin a first direction; a second detachable unit detachably supported inthe first detachable unit, the second detachable unit being receivableinto the first detachable unit in a second direction perpendicular tothe first direction, the second detachable unit including an exposedsurface that is at least partially exposed outside the first detachableunit when the first detachable unit is received in the first detachableunit; a memory accessible through one or more access terminals arrangedon the exposed surface, the one or more access terminals coming intocontact with the one or more contact terminals of the main body so as toestablish signal communication between the memory and the memoryaccessing unit.
 35. The apparatus of claim 34, wherein the memoryaccessing unit is configured to determine whether the first detachableunit is properly received into the main body by accessing the memory.36. The apparatus of claim 34, wherein the one or more contactscomprises at least one plate spring that retractably protrudes inwardlyinto the main body to be in pressing contact with the one or more accessterminals.
 37. The apparatus of claim 34, wherein the one or more accessterminals comprises a plurality of terminals, at least one of theplurality of terminals having its respective length longer than otherones of the plurality of terminals.
 38. The apparatus of claim 37,wherein the at least one of the plurality of terminals is locatedclosest to a bottom surface of the second detachable unit as comparedwith other ones of the plurality of terminals.
 39. The apparatus ofclaim 34, wherein the exposed surface comprises a first surface, onwhich the one or more access terminals are supported, and an obliquesurface formed upstream of the first surface with respect to the firstdirection so that the oblique surface comes into contact with the one ormore contacts first before the one or more access terminals as the firstdetachable unit moves into the main body.
 40. The apparatus of claim 39,wherein the oblique surface slopes downward as moving away from thefirst surface in the first direction.
 41. The apparatus of claim 39,wherein the memory accessing unit is an image forming apparatus, thefirst detachable unit is a developing cartridge usable in the imageforming apparatus, and the second detachable unit is a toner cartridge,and wherein the memory comprises a customer replaceable unit monitor(CRUM).
 42. A memory device including a second unit received into afirst unit in a first direction, a memory being disposed on a third unitreceived into the second unit in a second direction so as to allow atransfer of a signal between the first unit and the third unit, thememory device comprising: four terminals formed on a portion of thethird unit exposed externally from the second unit while the third unitis mounted in the second unit at a predetermined length in the firstdirection.
 43. The memory device of claim 42, wherein one of the fourterminals adjacent to a bottom surface of the third unit is a groundterminal.
 44. The memory device of claim 43, wherein one of the fourterminals adjacent to an upper surface of the third unit suppliesvoltage.
 45. The memory device of claim 42, wherein the first unit is abody of an image forming apparatus, the second unit is a developingcartridge, and the third unit is a toner cartridge.
 46. The memorydevice of claim 42, wherein the first unit comprises a plurality ofcontacts to contact the four terminals of the memory device.
 47. Thememory device of claim 46, wherein an oblique surface is formed on thethird unit to absorb an impact between the four terminals and theplurality of contacts by coming into a pressing contact with theplurality of contacts when the second unit is mounted in the first unit.48. The memory device of claim 47, wherein the oblique surface is formedat a location ahead of the memory with respect to the second directionin which the second unit is mounted into the first unit.